Well, one aspect of Dragon Ball Super Bardock fanfiction could be exploring his backstory further. Maybe delving into his early days on Planet Vegeta and his relationships with other Saiyans. It could also show his potential power growth that we didn't see in the original series.
The 'Dragon Ball Super Broly Novel' is an interesting expansion of the Dragon Ball universe. It delves deeper into the character of Broly, his backstory, and his power. It also explores the relationships between the other main characters in the face of this new and extremely powerful adversary. The novel may include more detailed descriptions of the battles, which are always a highlight in the Dragon Ball series.
In this fanfiction scenario, it could be an extremely emotional encounter. Goku, who has grown so much in Dragon Ball Super, finally meeting his father Bardock. Maybe Bardock gets to see how his son has not only become a powerful Saiyan but also a protector of Earth. It could lead to some interesting exchanges about Saiyan heritage and the future of the Saiyan race.
A common reaction in fanfiction about Dragon Ball Super Broly is shock at his raw power. Many fans write about how other characters, like Goku and Vegeta, react when they first see Broly's incredible strength. For example, Goku might be excited to face such a powerful opponent, seeing it as a new challenge in his quest for greater strength.
One possible fanfiction could be about Cheelai's backstory. Maybe she was once a normal Saiyan on Planet Vegeta but was part of a lower - class family. She had to fight hard from a young age to survive. In the fanfiction, it could explore how her experiences on her home planet shaped her into the tough character we see in 'Dragon Ball Super Broly'.
A simple fanfiction idea could be that Broly and Cheelai start training together to become even stronger. They aim to be the top protectors in their part of the universe.
The 'what - if' scenario of Bardock becoming a main character instead of Goku. This allows for a whole new perspective on the Dragon Ball universe. We could see Bardock's take on dealing with the various villains and his own moral code in handling different situations.